With increasingly widespread deployment of advanced wireless mobile networks, such as 3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) network architectures, these networks are replacing wired networks as the main access networks of choice. Wireless mobile networks continue to adapt to accommodate increased data traffic in view of radio spectrum, which remains a scarce resource and will continue do so for the foreseeable future. Video consumption, in particular, has grown to account for almost 50% of network traffic in cellular networks. Consequently, techniques that enable efficient use of the cellular spectrum and delivery of videos are invaluable to any cellular service provider.
Recent trends in wireless mobile networks are adopting point-to-multipoint services, in which data is transmitted from a single source entity to multiple recipients. Transmitting the same data to multiple recipients allows network resources, including the scarce radio spectrum, to be shared. One such example includes an LTE broadcast service, referred to as an evolved Multimedia Broadcast/Multicast service (eMBMS), disclosed in 3GPP TS 23.246, incorporated herein by reference in its entirety.
In particular, MBMS is a point-to-multipoint service providing a broadcast mode, in which a unidirectional point-to-multipoint transmission of data is established from a single source entity to all users in a broadcast service area. The MBMS also includes a multicast mode, in which a unidirectional point-to-multipoint transmission of data from a single source point to a multicast group in a multicast service area. Multicast mode can include a possibility for the network to selectively transmit to cells within the multicast service area which contain members of a multicast group.
FIG. 1 depicts an illustrative embodiment of reference architecture 100 to support the MBMS bearer service with eUTRAN and UTRAN. FIG. 1 was obtained from 3GPP TS 23.246. The wireless network 100 include radio access network (E-UTRAN) 102 that communicates wirelessly with mobile devices 104a. The reference architecture 100 includes a BM-SC 108, a Multimedia Broadcast/Multicast Service Gateway (MBMS GW) 110, a Mobility Management Entity (MME) 112, and a combined Packet Data Network (PDN) gateway 114.
The BM-SC 108 traditionally provides functions for MBMS user service provisioning and delivery. The BM-SC 108 issues session start request is provided on a SGmb diameter based interface. The MBMS-GW 110 traditionally provides an interface for entities using MBMS bearers through the SGi-mb (user plane) reference point and an interface for entities using MBMS bearers through the SGmb (control plane) reference point. The MBMS-GW 110 also traditionally facilitates IP multicast distribution of MBMS user plane data to E-UTRAN nodes (e.g., M1 reference points).
The MBMS-GW 110 responds to the BM-SC with session response. The MBMS-GW 110 then sends the session start request to a Mobility Management Entity (MME) on a Sm GTPv2-C based interface. The MME 112 then sends the session start request to the E-UTRAN 102 on an M3 Stream Control Transmission Protocol (SCTP) based interface. The E-UTRAN 102 sends the session start response to MME 112, which sends it to the MBMS GW 110.
In a traditional LTE-Broadcast network design, the BM-SC 108 initiates the session start request towards the MBMS-GW 110 on the SGmb diameter based interface to indicate the impending start of user data corresponding to a specific broadcast service. MBMS-GW 110 responds to the BM-SC 108 with session response. The MBMS-GW 110 then sends the session start request on the Sm interface to the MME 112. The MME 112 then sends the session start request on the M3 interface to the E-UTRAN 102. The E-UTRAN 102 sends the session start response to the MME 112, which will then send it to the MBMS GW 110.
There are 3 layers of control plane messaging with 3 different interfaces and protocol types used in establishing the MBMS session start request from the BM-SC to the eNBs. Upon successful establishment of the session and radio resource allocation, the eNB can join the transport network IP multicast address to receive the user data from MGW.